symmetriccipher Algorithm

The Symmetric Cipher Algorithm, also known as symmetric encryption, is a cryptographic technique that employs the same secret key for both the encryption and decryption processes. This type of encryption is widely used due to its efficiency and speed, especially when dealing with large amounts of data. The symmetric cipher algorithm relies on a well-defined set of rules, which enables the transformation of plaintext data into an unreadable format (ciphertext) and the subsequent conversion of ciphertext back to its original form (plaintext) using the same key. Common symmetric cipher algorithms include Advanced Encryption Standard (AES), Data Encryption Standard (DES), and Triple Data Encryption Standard (3DES). In symmetric encryption, the security of the data relies heavily on the secrecy of the shared key. Both the sender and the receiver must have access to the key, which can be a potential vulnerability if it falls into the wrong hands. To mitigate this risk, secure key exchange protocols, such as the Diffie-Hellman key exchange, are often employed to safely share the secret key between parties. Despite this vulnerability, symmetric encryption remains an essential and widely-used method for securing data and communications, particularly in bulk encryption, where its speed and efficiency outperform its counterpart, asymmetric encryption, which uses different keys for encryption and decryption.
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.

use buffer::{BufferResult, RefReadBuffer, RefWriteBuffer};
use cryptoutil::symm_enc_or_dec;

pub trait BlockEncryptor {
    fn block_size(&self) -> usize;
    fn encrypt_block(&self, input: &[u8], output: &mut [u8]);
}

pub trait BlockEncryptorX8 {
    fn block_size(&self) -> usize;
    fn encrypt_block_x8(&self, input: &[u8], output: &mut [u8]);
}

pub trait BlockDecryptor {
    fn block_size(&self) -> usize;
    fn decrypt_block(&self, input: &[u8], output: &mut [u8]);
}

pub trait BlockDecryptorX8 {
    fn block_size(&self) -> usize;
    fn decrypt_block_x8(&self, input: &[u8], output: &mut [u8]);
}

#[derive(Debug, Clone, Copy)]
pub enum SymmetricCipherError {
    InvalidLength,
    InvalidPadding
}

pub trait Encryptor {
    fn encrypt(&mut self, input: &mut RefReadBuffer, output: &mut RefWriteBuffer, eof: bool)
        -> Result<BufferResult, SymmetricCipherError>;
}

pub trait Decryptor {
    fn decrypt(&mut self, input: &mut RefReadBuffer, output: &mut RefWriteBuffer, eof: bool)
        -> Result<BufferResult, SymmetricCipherError>;
}

pub trait SynchronousStreamCipher {
    fn process(&mut self, input: &[u8], output: &mut [u8]);
}

// TODO - Its a bit unclear to me why this is necessary
impl SynchronousStreamCipher for Box<SynchronousStreamCipher + 'static> {
    fn process(&mut self, input: &[u8], output: &mut [u8]) {
        let me = &mut **self;
        me.process(input, output);
    }
}

impl Encryptor for Box<SynchronousStreamCipher + 'static> {
    fn encrypt(&mut self, input: &mut RefReadBuffer, output: &mut RefWriteBuffer, _: bool)
            -> Result<BufferResult, SymmetricCipherError> {
        symm_enc_or_dec(self, input, output)
    }
}

impl Decryptor for Box<SynchronousStreamCipher + 'static> {
    fn decrypt(&mut self, input: &mut RefReadBuffer, output: &mut RefWriteBuffer, _: bool)
            -> Result<BufferResult, SymmetricCipherError> {
        symm_enc_or_dec(self, input, output)
    }
}

LANGUAGE:

DARK MODE: